The invention relates to an adjustable holding device for on-board computers in motor vehicles, in particular for laptop or notebook computers, consisting of a support construction with a table plate located at the top end of said construction for demountably and remountably holding the on-board computer in the interior of the motor vehicle in the desired working position with respect to an occupant of the motor vehicle operating the on-board computer.
For adjusting the desired working position, the table plate is supported on the remaining support construction particularly in such a way that it can be adjusted sideways and with respect to its level of height and depth, and locked in the working position so selected in at least one preferred inclined position like a lectern.
The holding device furthermore comprises a fastening system on the lower end of the support construction for securing the latter on supporting surfaces in or near the floor region of the interior of the motor vehicle.
A holding system according to the features of claim 1 outlined above is known from DE-A1-44 21 039 [1] and DE design patent GM 297 08 702.9 [2]. According to said prior art, the support construction is designed in the form of a support arm or vertical tube with a lockable swivel arm on the top end, whereby a ball joint or inclining joint (which can be locked in position as well) for a table top or console holding the laptop or notebook computer is located on the outer end of the swivel arm. The vertical tube is fastened with its lower end on the wall of the driveshaft tunnel preferably in the position in front of the front-seat passenger, and partly also on the center console located above said driveshaft tunnel, and because of the inclined and curved or tapered way in which the wall of the driveshaft tunnel is extending, it can be adjusted with respect to its alignment by means of the fastening system. Drilling holes into the wall of the driveshaft tunnel for screws for anchoring the vertical tube is not deemed desirable in many cases because this will leave visible marks after the holding device has been removed. When the vehicle is sold as a used car, such marks represent to the potential buyer an additional depreciation of the vehicle""s value if such a buyer cannot himself use the drilled holes in the tunnel wall for mounting his or her own computer holding device, or simply does not want them.
In connection with another known holding device for on-board computers according to EP-A1-0 182 413 [3], a foot-side support for anchoring the support construction on the bottom side is screwed to the floor of the vehicle, for which purpose holes are drilled into the floor of the vehicle.
With respect to the holding devices according to [1] to [3] mentioned above, it is necessary to take into account, furthermore, that a large group of customers for on-board computers and their holding devices are field service employees, whose motor vehicles are often leased automobiles. Such motor vehicles have to be returned with as little damage as possible once a lease contract has expired, so it is impossible to drill holes into the wall of the driveshaft tunnel or floor of the vehicle.
Furthermore, a holding device with a pivotable and vertically adjustable support construction for a laptop or the like in a passenger car is known from DE-A1-195 10 339 [4]. Here, a clamped console is clamped in the foot space of the front-seat passenger in such a way that the pivoting laptop support can be reached by both the front-seat passenger and the driver. With this known holding device according to [4], no holes need to be drilled in support walls of the vehicle; however, because of its gear mechanisms for four extendable support legs and the stable housing, this clamped console is relatively heavy and, therefore, subjected to increased forces due to mass occurring during acceleration and braking of the vehicle, so that increased requirements have to be satisfied with respect to the bottom-side clamping of the clamped console. Now, the two pairs of support legs, which are supported on both sides of the clamped console where they can be extended and retracted, are provided on their free ends with round support dishes having a relatively small diameter. Said support dishes, however, because of their small friction grip surfaces, cannot prevent the clamping from getting loose, or the clamped console from getting skewed in spite of their skid-proof coating, especially not during hard braking of the vehicle, all the less so in light of the fact that the support construction is clamped xe2x80x9crigidlyxe2x80x9d by means of quick-action clamping devices, and that this type of clamping involves a four-point clamping system that can be statically controlled only with difficulty. It comes as no surprise that such a holding device with a clamped console has not yet appeared in the market for passenger car accessories.
The invention is based on the problem of avoiding the problems outlined above and to equip an adjustable holding device for on-board computers in motor vehicles with a fastening system of such a type that no drilling and screwing to the wall of the driveshaft tunnel or bottom metal sheet of the vehicle is required for mounting the support construction, on the one hand, and that operationally safe fastening in a passenger car (or also in a truck) is made possible by a specially designed clamping system, on the other hand, such a fastening arrangement retaining its position in the presence of any occurring acceleration and braking forces.
A further problem is to develop the basic concept of the holding device with its fastening system in such a way that it is possible to easily and quickly adapt it to support surfaces in the motor vehicle that differ with respect to their directions and spacings, i.e., to allow it to be adapted to differently shaped and spaced support surfaces of the driveshaft tunnel and door sills.
According to another problem, the holding device as defined by the invention is to be suited for quick installation and quick removal, which is understood to mean that it is to be mountable or removable in less than 60 seconds.
According to yet another problem, the constructional setup of the fastening system for the holding device is to permit a lightweight construction, so that during acceleration or braking of the motor vehicle, the inertia forces to which the fastening system is subjected to will be relatively low.
Now, the object of the invention is an adjustable holding device for on-board computers in motor vehicles, in particular for laptop or notebook computers, consisting of a support construction with a table top plate at its upper end for demountably and remountably holding the on-board computer in the interior of the motor vehicle in the desired working position with respect to a vehicle occupant operating the on-board computer; and, furthermore, a fastening system on the lower end of the support construction for mounting the support construction on support surfaces within or near the floor region of the interior of the vehicle, whereby the fastening system is a clamping system with at least one clamping strut, which can be clamped on support surfaces of the interior of the vehicle opposing each other with a spacing and extending at least approximately perpendicular to the floor of the vehicle; and whereby the clamping strut is provided for said purpose on each of its two ends with a contact-pressure element arrangement, and the contact-pressure elements are provided for said purpose with outer counter support surfaces for pressingly abutting the support surfaces, and the clamping system is provided with means for contact pressure-generating enlargement of the spacing of the contact-pressure elements relative to each other during installation, or for contact pressure-reducing reduction of the spacing of the contact-pressure elements relative to each other during removal of the clamping system, as stated in the introductory part of claim 1.
In connection with such a holding device, the invention according to the characteristic part of claim 1 for solving the problem posed consists in that the clamping system is a spreading system, and the clamping strut is a spreading strut having at least two spreading levers connected by a lockable and releasable hinged joint, of which at least one lever can be pre-adjusted with respect to its length in such a way that the spreading strut can be brought into a bent-in ready position, with its contact-pressure elements spaced from the associated support surfaces, and the spreading strut can be stretched to a length by means of depressing the hinged joint that will generate the required contact pressure force, whereby the stretched and mounted spreading strut can be fixed in its expanded position by locking the hinged joint.
Advantageous further developments are specified in the dependent claims 2 to 21.
The advantages achievable with the invention are mainly to be seen in that a very short time span is required for mounting and removing the holding device with its fastening system. Furthermore, no tools are required for installing and removing the device (a wrench or a spindle drive motor would be required with a worm gear, which means additional expenditure).
Such a spreading system also may be, for example a scissors-type lever system, whose scissors arms are pivot-jointed with each other, whereby the scissors arms form a rhombic framework, or several rhombic frameworks one following the other in the direction of expansion. When such frameworks are flattened, the length of the scissors-type lever system is increased, or, vice versa, reduced if the joints of the rhombic frameworks opposing each other move farther apart from each other. It is preferably possible also to employ pneumatic (and, if need be, hydraulic) piston-cylinder systems with small manual pumps for changing the length of the expanding strut or scissors lever system, whereby the position of the piston is usefully secured by a releasable locking pawl engaging the locking teeth of a toothed rack when the holding system is in the spread, clamped position.
Additional advantages achievable with the invention, among others, are to be seen in that the holding device can be quickly installed by means of screwless quick expansion (which means screw holes are avoided), and also removed again by quickly detaching the spreading system. The expansion system can be adapted-to different spacings between the support surfaces opposing each other in the interior of the vehicle, and it can be used also with support surfaces extending slanted, curved or in some other oblique way in relation to the longitudinal axis of the spreading strut, as it is the case, for example in connection with the walls of drivetrain tunnels. Within the meaning of the invention, such drivetrain tunnel walls still extend xe2x80x9capproximately verticalxe2x80x9d, i.e. even if the tangent applied to the support surface and a vertical longitudinal plane jointly enclose an angle of about up to 25 degrees. It is shown below in detail that fastening through expansion is reliably possible even in such a case. A further advantage consists in that the holding device with its spreading system can be mounted in a normal (four-or five-seat) passenger motor vehicle in several basic positions: in front of the front passenger seat or in front of the left or right half of the rear seat bench, so that the on-board computer can be operated by the driver (which is the most frequent case) or by an occupant sitting in the back of the vehicle. In connection with motor vehicles with a cardan drive shaft, it is possible according to another feature of the invention to clamp the expanding system with its contact-pressure elements between support surfaces in the region of the door sill, on the one side, and support surfaces in the region of the cardan shaft, on the other. But the spreading system as defined by the invention can be installed also in motor vehicles without a cardan-type drive shaft (vehicles with front drive, or with a rear engine): either other center support surfaces are present instead of the wall of the cardan driveshaft tunnel, or the expanding system extends from one door sill up to the opposite door sill, in which case it has an extended spreading strut.
The following special advantages are pointed out in connection with the dependent claims 15 to 21:
Simplification of the locking of the hinged joint when the spreading strut is in its extended position, and simplified unlocking of the latter (in case of removal) without sacrificing the reliability of the lock.
Spring-elastic yielding of the spreading strut in its longitudinal direction is made possible with a simple construction.
Improved coupling of the floor-side fastening system or spreading strut with the support construction, in particular a vertical tube, so that the manual actuation for installing and removing the vertical tube is simplified, and defined clamping forces will always appear in this connection in the coupling site.
Variability of the working position of the on-board computer with respect to its level of height if desired by the user, by vertically adjusting the upright tube of the support construction having the table top plate holding the on-board computer supported at its top end.
The handling of the holding device is improved overall by said advantages. Because of the lever extension of the one spreading lever (see claim 15), the hinged joint can be locked at a relatively large spacing from said hinged lock, which provides a large moment for unlocking, and quick and comfortable locking and unlocking is made possible by actuating the knurled screw. Owing to the spring elements inserted between the two spreading levers, the spreading rail can be installed and removed in a very reliable manner without permitting excessive compulsive forces to occur, and tolerance compensation ensues in the mounted condition over the length of the spreading rail within the zone of the spring path, as well as a possibility for rating the contact pressure forces because of the selected spring force. The use of an eccentric lever-type clamping device for securing the coupling between the vertical tube and the base socket results in clamping forces acting on the coupling in a predefinable way, and such forces always remain the same even if the system is installed and removed several times, as well as in user friendliness in the sense of quick installation and removal.